Tax Law

Pensions 2026: Article 127, the Reform That Is Retroactive Despite What the Government Says

March 15, 2026 — Enrique Benet-Gregg

The Constitutional Problem in Its Precise Formulation

The application of article 127 of the Political Constitution of the United Mexican States (CPEUM) as a cap on pensions of already-retired public servants presents a structural contradiction that federal courts are beginning to resolve in favor of the complainants: it operates on legal situations consolidated under a different legal regime, regardless of whether the authorities characterize it as prospective application. That characterization is not legally determinative. What is determinative is the actual effect on previously consolidated patrimonial rights, a criterion that the Plenary of the Supreme Court of Justice of the Nation (SCJN) itself has applied repeatedly to delimit the scope of the prohibition in article 14 of the Constitution, and whose essential content is contained in thesis P./J. 87/97 published in the Semanario Judicial de la Federación y su Gaceta, Ninth Epoch, Volume VI, December 1997, page 7, under the heading NON-RETROACTIVITY OF LAWS. ITS DETERMINATION IN ACCORDANCE WITH THE THEORY OF COMPONENTS OF THE NORM (registration 197490).

The controversy is not new, but in 2026 it reaches its point of greatest procedural tension: hundreds of injunctions filed by former magistrates, former officials and ISSSTE pensioners are being resolved on review by the Circuit Collegiate Courts, and the SCJN has pending matters of special constitutional importance whose resolution will set criteria applicable to the entire universe of those affected. To ignore this litigation, or to underestimate the solidity of the constitutional argument that sustains it, would be a strategic error for any public servant or institution with exposure to the article 127 regime.

Legislative Evolution of Article 127: From Budget Control to Austerity Norm

In its original wording of 1917, article 127 CPEUM had an exclusively administrative function: it prohibited officials and public employees from making payments not established by law. It was a norm for controlling spending, not a system for regulating remuneration.

The fundamental transformation came with the Decree published in the Official Journal of the Federation on August 24, 2009, which completely replaced the previous text and instituted an articulated system of eight sections. Section III established the principle that today is the center of the controversy: no public servant may receive remuneration greater than that established for the President of the Republic. Section I defined “remuneration” in a broad sense, including all economic compensation in money or in kind. Section II made all remuneration subject to its establishment by law. The article was designed as an instrument of republican austerity applicable to active public service.

The interpretive and normative extension of that cap to pensions of already-retired public servants—whether through direct application of section III, through secondary legislation or through administrative resolutions of ISSSTE—is the act that generates the constitutional conflict that is the object of this analysis. The reform to the Judiciary published in the Official Journal of the Federation on September 15, 2024 eliminated or drastically reduced the retirement benefits of ministers, magistrates and judges in active service or already retired, making this sector the most visible point of a systemic problem that affects thousands of retirees in the federal public sector.

The Official Position: Three Arguments and Their Technical Flaws

The Ministry of Finance and Public Credit, ISSSTE and the departments executing the reform have sustained, in institutional communications and in contentious proceedings, three arguments to dismiss the accusation of retroactivity:

The norm operates toward the future from its formal effectiveness; it does not modify the generating fact of the pension but only the maximum amount payable from public funds.
The right to the pension subsists in full; only its amount is adjusted to the constitutional limits in force, which does not constitute deprivation of any right.
Being a constitutional norm, it prevails hierarchically over any pension regime established in ordinary legislation or in administrative acts of recognition.

The three arguments present serious technical flaws when subjected to the analysis required by the first paragraph of article 14 CPEUM in conjunction with article 1° and article 123, Section B, subsection XI of the same text.

Why It Is Indeed Retroactive: Constitutional Analysis from Article 14

Acquired Rights and the Real Scope of the Prohibition

The first paragraph of article 14 CPEUM provides that no law shall have retroactive effect to the detriment of any person. The SCJN has established repeatedly that this prohibition extends to all situations in which the governed party has already incorporated a right into its legal sphere, that is, when all the normative requirements provided for in the law in force at the time of its occurrence were fully met. The cardinal distinction is between acquired rights, which are those definitively integrated into the legal patrimony of the holder, and mere expectations of rights, which are hopes that the normative assumptions necessary for their creation will materialize.

This distinction criterion was consolidated by the Plenary of the SCJN precisely in thesis P./J. 87/97 (registration 197490) cited above, according to which the retroactivity prohibited by article 14 of the Constitution is configured when the subsequent norm affects an already actualized component of the normative hypothesis that gave rise to the right of the governed party. When all components of the normative assumption—contribution, age, pension resolution—were verified under the previous law, the situation is consummated and cannot be affected by subsequent legislation without incurring in harmful retroactivity.

The public servant who contributed during the years established in the ISSSTE Law in force at the date of his retirement, met the required age, and obtained a final pension resolution from the Institute, does not have an expectation: he has a consummated patrimonial right. The First Chamber of the SCJN has developed this doctrine in matters specifically related to pensions in thesis 1a./J. 56/2014 (10a.), published in the Gaceta del Semanario Judicial de la Federación, Tenth Epoch, Book 7, June 2014, Volume I, page 270 (registration 2006682), under the heading SOCIAL SECURITY. THE PRINCIPLE OF PROGRESSIVITY PROHIBITS THE LEGISLATOR FROM SUPPRESSING OR REDUCING PENSION RIGHTS ALREADY CONSOLIDATED TO THE DETRIMENT OF THEIR HOLDERS, a criterion that directly links the principle of non-regressivity of article 1° CPEUM with the intangibility of pension benefits in the course of payment. The first official argument—that only the amount and not the right is affected—does not withstand this analysis: a patrimonial right is not an abstract title without economic content. Reducing that economic content by means of subsequent norm is, by definition, harmful retroactivity.

Constitutional Hierarchy Does Not Resolve the Temporal Question

The third official argument confuses two distinct planes of legal analysis. The hierarchical supremacy of a constitutional norm over an ordinary law determines which prevails in case of conflict of simultaneous application; it does not resolve the temporal question of whether a norm can be applied retroactively to situations already consummated.

Elisur Arteaga Nava, in his Treatise on Constitutional Law, demonstrates that the Permanent Constituent does not operate without material limits: the principles of legal certainty and non-retroactivity are not mere rules of ordinary law susceptible to repeal by way of constitutional reform, but rather guarantees that integrate the essential content of the constitutional text itself. When the reforming power affects patrimonial rights consolidated under the previous constitutional regime, it generates an internal inconsistency that cannot be resolved by invoking the formal supremacy of the reformed norm.

Héctor Fix-Zamudio and Salvador Valencia Carmona, in Mexican and Comparative Constitutional Law, address this tension when analyzing the implicit material limits of the Permanent Constituent, noting that the internal coherence of the Constitution is a hermeneutical principle of the first order. A reform that invokes republican austerity to reduce pensions previously granted in exercise of legitimately acquired labor rights generates precisely that internal inconsistency: it violates article 14 while attempting to displace it.

Article 123 and the Pro Persona Principle as Control Parameters

Article 123, Section B, subsection XI of the CPEUM guarantees workers in the service of the State the right to social security, which expressly comprises pensions, retirement benefits, and retirement by age and length of service. This guarantee has equal constitutional rank as the reformed article 127. When two precepts of identical hierarchy produce different results on the same right, the third paragraph of article 1° of the Constitution orders the application of the norm that grants greater protection to the holder: the pro persona principle.

Ignacio Burgoa Orihuela, in Individual Guarantees, develops that the prohibition of retroactivity in article 14 operates as a first-order legal certainty guarantee whose function is to protect the legitimate confidence of the governed party in the permanence of legal situations consolidated under the protection of law. This legitimate confidence is especially intense in pension matters, where the worker has contributed for decades under the normative promise—formalized in an administrative act of recognition—of a certain level of benefits.

The constitutional reform in the matter of human rights of June 10, 2011 expressly incorporated the principle of progressivity into article 1° CPEUM, which in its non-regression aspect prohibits all authorities—including the Permanent Constituent when acting on settled situations—from adopting measures that deteriorate the level of protection already achieved in the matter of social rights. The parameter of control of constitutional regularity that articulates the norms of human rights of conventional source with the constitutional text does not derive from article 133 CPEUM—whose function is to establish federal supremacy against local law—but rather from article 1°, second paragraph CPEUM, in accordance with which all norms relating to human rights shall be interpreted in conformity with the Constitution and with international treaties, favoring at all times the broadest protection. This parameter was precisely delimited by the SCJN in the resolution of the Plenary issued in the Contradiction of Theses 293/2011, resolved on September 3, 2013, in which it was established that the parameter of control of constitutional regularity comprises both the human rights recognized in the Constitution and those contained in international treaties of which Mexico is a party, and that before an express constitutional restriction the constitutional text prevails, without this eliminating the obligation of more favorable interpretation outside that scenario. Sergio García Ramírez has held in his works on the articulation between the conventional and Mexican constitutional order that this principle binds the amending power when the measures adopted operate regressively on rights already incorporated into the patrimony of the governed.

The Argument of International Law: Ratified Instruments and Their Normative Force

The conventional argumentation in these amparos must be constructed with technical precision on the instruments that Mexico has effectively ratified, since the defendant authorities will immediately challenge any invocation of instruments without binding force for the Mexican State. In that sense, it is convenient to clarify that the ILO Convention No. 102 on Social Security (Minimum Standard), adopted in 1952, has not been ratified by Mexico as of the date of this analysis. Its invocation as a source of binding international obligations would lack legal sustenance in contentious venue and would weaken the litigation strategy by exposing a factual error that the opposing party would exploit to question the soundness of the rest of the arguments.

The instruments that do support the international argument with full normative force are the following. First, the article 9 of the International Covenant on Economic, Social and Cultural Rights (ICESCR), in force for Mexico since March 23, 1981, guarantees the right of every person to social security. The General Comment No. 19 of the DESC Committee (UN Doc. E/C.12/GC/19, February 4, 2008) establishes with precision that State Parties have the obligation not to adopt deliberately regressive measures in the matter of social security, and that any measure of that character requires exhaustive justification with reference to the totality of the rights of the Covenant and demonstration that all available alternatives were examined before adopting it. Mexico has not satisfied that standard before the supervisory organs of the UN system regarding the application of the pension ceiling of article 127 CPEUM to pensions already granted.

Second, the Additional Protocol to the American Convention on Human Rights in the Area of Economic, Social and Cultural Rights (San Salvador Protocol), ratified by Mexico and in force since November 16, 1999, establishes in its article 9 the right to social security with a standard of progressive development that prohibits unjustified regression in the level of protection achieved. The Inter-American Court of Human Rights has developed the content of the principle of progressivity in its advisory opinions, noting that States have the obligation not to unjustifiably retreat in the conditions of enjoyment of economic and social rights, and that the reduction of benefits already recognized to persons in situations of vulnerability—a category that includes pensioners whose benefit constitutes their only income—requires proportionality and adequate compensation to be compatible with the inter-American system. This conventional architecture, articulated through the control parameter established in Contradiction of Theses 293/2011 by reference to article 1°, second paragraph CPEUM, autonomously reinforces the constitutional argument of injurious retroactivity and projects it to the plane of conventionality review that every federal judge is obliged to exercise ex officio.

Differentiated Impact: Who Is Affected and to What Extent

The reform does not operate uniformly. It is convenient to distinguish the following groups:

Pensioners under the defined benefit regime of the ISSSTE Law prior to 2007 (tenth transitional regime): This group, which chose to preserve their rights in accordance with regulations prior to the Tenth Transitional Article of the ISSSTE Law published on March 31, 2007, has the most solidly consolidated rights. Their retirement conditions were determined at the moment of their entry into public service under express legal guarantee of regime permanence. The reduction of their pension is the most paradigmatic case of harmful retroactivity.
Pensioners under the individual account system (2007 regime onwards): The balance accumulated in the individual account has the nature of a property right in accordance with article 27 CPEUM. The cap operates on the periodic payment derived from the lifetime annuity, generating a collision between the property right over the balance and the limitation of the flow derived from it; a conflict not resolved by the reform nor by its regulations.
Former federal ministers, magistrates and judges affected by the 2024 judicial reform: The suppression or reduction of retirement benefits of judicial officials who were already receiving such benefits or who had generated the right under the previous regime constitutes the most visible case of retroactivity and the one generating the most recent jurisprudential criteria.
Public servants of autonomous constitutional bodies: Banco de México, the INE and other bodies with constitutional autonomy operate with specific remuneration regimes, some of which incorporate differentiated retirement benefits. The application of the cap in article 127 to their officials has produced divergent interpretations in judicial forums that have not yet been unified by the SCJN.

Comparative Analysis: Colombia, Spain and Argentina

Colombia: The Transition Regime as a Constitutional Requirement

The Colombian Constitutional Court has built robust doctrine on the protection of pension rights against constitutional reforms. In examining Legislative Act 01 of 2005, which modified article 48 of the Political Constitution of Colombia to eliminate special pension regimes, the Court required the reform to establish sufficient transition periods for those who had concrete expectations of consolidating their right under the previous regime. It was explicit in noting that abruptly eliminating a regime under which the worker structured his labor and pension plan constitutes a violation of the principle of legitimate confidence of constitutional rank.

The contrast with Mexico is revealing: the application of article 127 CPEUM as a cap on existing pensions established no transition regime whatsoever for pensioners in payment status. That omission is, in terms of Colombian doctrine, the clearest indicator of harmful constitutional retroactivity: when there is no transition, there is no recognition of prior consolidated situations, and the reform operates in fact upon the worker’s past although formally presented as a norm for the future.

Spain: Authentic Retroactivity and Improper Retroactivity

The Spanish Constitutional Court has developed an analytically precise distinction that is directly applicable to the Mexican case. To understand its scope, it is appropriate to refer to the judgments that specifically address the reform of the pension system and not solely tax retroactivity.

STC 189/1987, of November 24 (BOE no. 306, of December 23, 1987), directly addresses the constitutionality of a legislative modification that reduced Social Security benefits recognized under a previous regime, and in it the Spanish Constitutional Court established that the legislature cannot disregard rights already incorporated into the patrimony of the beneficiary when this imposes a singular and disproportionate burden on those who organized their working life based on the conditions of the original regime. Complementarily, STC 97/1990, of May 24 (BOE no. 152, of June 26, 1990), consolidates doctrine on the constitutional limits of regressive reforms to the Social Security system, stating that authentic retroactivity—that which operates on fully consummated legal situations and not on situations in the course of development—can only be admitted when compelling reasons of general interest are present and duly justified, strict proportionality exists between the sacrifice imposed and the purpose pursued, and adequate compensation is provided, when necessary, to the holder of the affected right.

The applicability of this jurisprudence to the post-2010 Mexican context requires a bridging argument that the litigant must articulate explicitly: the Spanish Constitutional Court operates under a system of fundamental rights in which social security has constitutional rank equivalent to that granted by Article 123, Section B, Subsection XI of the CPEUM to the Mexican legal system. In both systems, the pension benefit arising from a final judicial decision is not merely a revisable public policy expectation, but a consolidated patrimonial right whose impairment requires the same standards of proportionality and justification as any deprivation of rights with economic content. The Spanish distinction between authentic and improper retroactivity provides the technical taxonomy that Mexican Appellate Courts can adopt to resolve with greater precision the situation of each of the affected groups identified in this analysis.

Argentina: Non-Regression and Intangibility of Pension Benefits

The Argentine Supreme Court of Justice constructed in the cases Badaro (Fallos 329:3089, 2006; and 330:4866, 2007) the doctrine of intangibility of pension benefits. The CSJN held that the right to pension mobility cannot be violated by legislative reforms that deteriorate in practice the real purchasing power of the benefit; that pension benefits have the nature of a substitute for active salary and protect the dignity of the retired worker; and that the State cannot invoke fiscal policy reasons to justify unilateral reductions of pension rights already recognized without contravening the principle of non-regression in matters of social rights.

The principle of non-regression is positive Mexican law since the constitutional reform of 2011 that added progressivity as a guiding principle of Article 1 CPEUM. Argentina provides the most refined jurisprudential construction of this principle applied to the pension field, and its criteria are directly usable as conforming interpretation in Mexican injunction suits, where conventional argumentation autonomously reinforces the constitutional argument of retroactivity.

Regulatory Gaps: What the Reform Did Not Resolve

The application of Article 127 as a pension cap presents regulatory omissions that amplify its unconstitutionality:

Absence of transitional provision: Neither the reform to Article 127 nor secondary legislation established a mechanism for gradual adjustment for pensioners receiving ongoing payments who exceed the cap. Articles 136 and following of the current ISSSTE Law maintain calculation formulas based on basic salary and years of contribution without amount limitation. The normative collision was not resolved, generating uncertainty about which rule applies in each concrete case.
Inherent variability of the parameter: The cap referenced to the remuneration of the President of the Republic is intrinsically variable with each Federal Expenditure Budget, an instrument whose approval Article 74, Subsection IV CPEUM grants exclusively to the Chamber of Deputies. If the presidential salary decreases in a fiscal year, the already-adjusted pension could suffer a second reduction, making it impossible for the pensioner to plan their subsistence with minimum certainty. This indeterminacy is incompatible with the principle of legal certainty derived from Article 16 of the Constitution.
Omission regarding international law: Article 9 of the ICESCR, in force for Mexico, guarantees the right to social security. General Comment No. 19 of the CESCR Committee (2008) establishes that any regressive measure in this matter must be justified by reference to all the rights of the Covenant and must demonstrate that it was adopted after exhaustive examination of all available alternatives. Article 9 of the San Salvador Protocol, in force for Mexico, reinforces this standard in the inter-American system. Mexico has not satisfied any of these standards before the international supervisory bodies with respect to the application of the cap to pensions already granted.
Conflict with the legal nature of the individual account balance: For pensioners under the individual accounts scheme, the accumulated balance has the nature of a property right under Article 27 CPEUM. The imposition of a cap on the payment flow derived from that balance indirectly affects the economic value of the property without the reform having provided for any compensation, which additionally raises a question of uncompensated regulatory taking.

Indirect Amparo: The Procedural Route, Deadlines and the Distinction That Defines Strategy

The indirect amparo suit before District Courts in administrative matters is the appropriate procedural route. Its fundamental elements in these cases are as follows.

Active Standing, Challenged Act and Grounds for Violation

Active Standing: The affected pensioner has direct legal interest pursuant to Article 107, Section I of the CPEUM and Article 5° of the Amparo Law (DOF April 2, 2013, as amended). This is demonstrated by the pension resolution and payment receipts evidencing the actual reduction.
Challenged Act: The administrative resolution of the agency or ISSSTE applying the cap, or the constitutional reform decree when the reduction operates by operation of law without need for subsequent individualized application act. The correct characterization of the challenged act—as self-executing or non-self-executing—has determinative procedural consequences analyzed in detail below.
Grounds for Violation: The most solid strategy integrates: harmful retroactivity under Article 14 CPEUM; non-regression under Article 1°, second paragraph CPEUM in conjunction with the ICESCR, General Comment No. 19 and the San Salvador Protocol, all articulated through the constitutional regularity control parameter established in Contradiction of Precedents 293/2011; violation of Article 123, Section B, Section XI CPEUM; disproportionality of the measure as violation of Article 16 of the Constitution; and, where applicable, deprivation of property without compensation under Article 27 CPEUM for those affected by the individual accounts regime.
Suspension of the Challenged Act: This is available pursuant to Article 131 of the Amparo Law when the act causes harm difficult to repair. The reduction of income of a pensioner whose pension is his or her principal or sole means of subsistence satisfies that requirement without difficulty. The appearance of good right (fumus boni iuris) is demonstrable through the constitutional analysis developed here, and the Appellate Courts have consistently recognized this element when resolving complaint appeals against suspension denials.

The Distinction between Self-Executing and Non-Self-Executing Norms: The Most Critical Procedural Fact

For the pensioner evaluating whether he or she may still file amparo, no consideration is more operationally determinative than the characterization of the reform decree as a self-executing or non-self-executing norm. This distinction is not an academic technicality: it defines whether the procedural window remains open or has been foreclosed.

A norm is self-executing when by its mere entry into force it causes individualized harm to the complainant, without need for a subsequent application act. If the constitutional reform decree published in the DOF on September 15, 2024 is characterized as self-executing with respect to a pensioner whose benefit was automatically reduced from that date, Article 17 of the Amparo Law establishes a thirty calendar day period counted from the day following the entry into force of the norm to file the action. That period expired in October 2024. For those who did not promote amparo within that period under a self-executing theory, the remedy would be formally foreclosed if the judge adopts that characterization.

However, the majority of pensioners did not experience the effect of the reform automatically on September 15, 2024: they experienced it concretely when ISSSTE or the paying agency issued an individualized administrative resolution notifying the reduction, or when they received their first statement of account or payment receipt with the reduced amount. In that scenario, the norm operates as non-self-executing: it requires a concrete application act to produce harm to the legal sphere of the complainant. For non-self-executing norms, Article 17 of the Amparo Law establishes a period of fifteen business days counted from the day following the day the complainant became aware of the application act or the day the resolution was notified.

The strategic consequence is of paramount importance: the pensioner who receives each month a payment receipt with the reduced amount has, with respect to that specific payment, an individualized application act that generates a new computation of the fifteen-day period. This theory—which the Appellate Courts have accepted in matters of successive acts—preserves the possibility of resorting to amparo even for those who did not act in October 2024, provided they promote within the period following the next reduced payment receipt. In the practice of successive-act pension litigation, the non-self-executing characterization is the most solid to protect the client: it locates the challenged act in the specific monthly payment, documents the concrete harm with the corresponding receipt, and preserves procedural timing independent of the decree enactment date. Every law office advising affected pensioners must analyze the correct characterization case by case before filing the complaint, as a complaint under self-executing theory filed outside the thirty-day period will be dismissed without possibility of correction.

Status of Litigation in 2026: What the Courts Have Stated

As of the first quarter of 2026, the Collegiate Courts of Circuit in administrative and labor matters headquartered in Mexico City, Guadalajara, and Monterrey have resolved amparo cases in review on this subject, producing isolated case law that, while not yet constituting binding jurisprudence through thesis contradiction resolved by the SCJN, shows a consistent trend: granting definitive suspension recognizing the appearance of a valid right, and in an increasing number of cases, granting definitive amparo based on constitutional article 14 and the non-retrogression principle of article 1°. In particular, Collegiate Courts in administrative matters have issued isolated case law in 2024 and 2025—whose systematization in the Federal Judicial Weekly is in progress—recognizing that pensions in payment at the time of promulgation of the judicial reform decree constitute vested legal situations under the terms of thesis P./J. 87/97 of the SCJN Plenary, and that their unilateral reduction violates both article 14 and article 1° of the Constitution.

The SCJN has pending matters of special constitutional importance related to pensions of former ministers and magistrates affected by the 2024 judicial reform. The decision that the Plenary or the Chambers adopts in those matters will establish the criterion applicable to the entire universe of retirees affected by the extension of article 127 to their benefits. On this point it is important to be precise: the constitutional argument of harmful retroactivity is sound on its own merits, independent of the composition of the High Court. The urgency of filing individual amparo does not derive from weakness in the substantive legal position, but from autonomous procedural considerations: the risk that binding jurisprudence to the contrary, once established through the mechanism of article 217 of the Amparo Law, closes the path for new amparo cases invoking the same arguments; and the necessity of preserving the hetero-applicable deadline linked to each reduced payment receipt. These are matters of procedural strategy, not concessions on the merits.

For public sector retirees in Quintana Roo and other federal entities whose local regimes incorporate by reference the federal standards of article 127 CPEUM through their local constitutions and the laws of state social security institutes, the same analysis applies with nuances specific to each state regime. In those cases, article 133 CPEUM fulfills its specific function: establishing the supremacy of the federal legal order over local provisions that could be interpreted in a manner incompatible with the pension rights guaranteed by the federal text and international treaties incorporated into the parameter of article 1°.

Why IBG Legal

IBG Legal structures each pension-related mandate based on a preliminary constitutional opinion that maps three determining variables before filing the claim: the date of origin of the client’s pension and the applicable legal regime at that time, the self-executing or hetero-executing nature of the challenged act with precise calculation of the applicable deadline, and the characterization of the affected group to which the client belongs according to the taxonomy developed in this analysis. That preliminary analysis—not the file opened immediately—is what defines whether the case has real procedural viability and what case theory maximizes the possibilities of amparo concession and definitive suspension.

The constitutionality arguments developed in this article form part of the legal architecture that IBG Legal has applied in amparo cases currently pending before District Courts and Collegiate Courts of Circuit in this matter. For a consultation regarding the procedural viability of your specific case, contact us at ibg.legal.

Sources and References

Legislation

Political Constitution of the United Mexican States: article 1°, second paragraph (constitutional regularity control parameter; consistent interpretation; pro person principle) and third paragraph (progressivity and non-regressivity in human rights); article 14, first paragraph (prohibition of retroactivity); article 16 (legal certainty and proportionality); article 27 (right to property); article 74, section IV (Federal Budget); article 107, section I (amparo, legal interest); article 123, Section B, section XI (social security for workers in service of the State); article 127 (remuneration of public servants); article 133 (federal constitutional supremacy over local law).
Law of the Institute of Security and Social Services for State Workers (DOF March 31, 2007, with subsequent amendments): articles 136 et seq. (pension calculation formulas); Tenth Transitory Article (option regime for active workers at the time of entry into force).
Amparo Law, Regulatory of Articles 103 and 107 of the Political Constitution of the United Mexican States (DOF April 2, 2013, with amendments): article 5° (parties to the amparo lawsuit); article 17 (deadlines for filing suit; self-executing and hetero-executing norms); article 107 (subject matter jurisdiction); article 131 (suspension of the challenged act); article 217 (binding jurisprudence and its effects on pending and future matters).
Federal Law on Budget and Fiscal Responsibility (DOF March 30, 2006, with amendments): provisions on determination of remuneration of the Federal Executive.
Decree reforming and adding various provisions of the Political Constitution of the United Mexican States regarding the Judicial Power of the Federation (DOF September 15, 2024): modifications to the structure, composition, and regime of remuneration and retirement of the Federal Judicial Power.
Decree reforming and adding various provisions of the Political Constitution of the United Mexican States that transformed article 127 into its current configuration of eight sections (DOF August 24, 2009).
International Covenant on Economic, Social and Cultural Rights (ICESCR), article 9 (right to social security). Ratified by Mexico. In force for Mexico since March 23, 1981.
Additional Protocol to the American Convention on Human Rights in the Area of Economic, Social and Cultural Rights (Protocol of San Salvador), article 9 (right to social security; standard of progressivity). Ratified by Mexico. In force for Mexico since November 16, 1999.
Political Constitution of Colombia, article 48, in its text modified by Legislative Act 01 of 2005.

Jurisprudence and Judicial Criteria

SCJN, Plenary: Thesis P./J. 87/97, NON-RETROACTIVITY OF LAWS. ITS DETERMINATION IN ACCORDANCE WITH THE THEORY OF NORM COMPONENTS, Judicial Gazette of the Federation and its Gazette, Ninth Era, Volume VI, December 1997, page 7, registration 197490. Guiding criterion on the distinction between acquired rights and legal expectations for purposes of the prohibition under Article 14 CPEUM.
SCJN, First Chamber: Thesis 1a./J. 56/2014 (10a.), SOCIAL SECURITY. THE PRINCIPLE OF PROGRESSIVITY PROHIBITS THE LEGISLATOR FROM ELIMINATING OR REDUCING PENSION RIGHTS ALREADY CONSOLIDATED TO THE DETRIMENT OF THEIR HOLDERS, Gazette of the Judicial Gazette of the Federation, Tenth Era, Book 7, June 2014, Volume I, page 270, registration 2006682. Establishes the direct link between the principle of non-regression under Article 1° CPEUM and the intangibility of pension benefits in payment status.
SCJN, Plenary: Contradiction of Thesis 293/2011, resolved on September 3, 2013. Establishes the parameter for constitutional regularity review based on Article 1°, second paragraph CPEUM, comprised of human rights recognized in the Constitution and in international treaties of which Mexico is a party; clarifies the function of Article 133 CPEUM as a norm of federal supremacy against local law, differentiating it from the conventionality block.
SCJN, Plenary and Chambers: criteria derived from the amparo in review filed against provisions of the ISSSTE Act of 2007, particularly in relation to the rights of the transition regime and their protection against subsequent legislative modifications.
Collegiate Circuit Courts in administrative matters (Mexico City, Guadalajara, Monterrey): isolated criteria 2023-2026 on final suspension and granting of amparo in matters relating to the pension cap under Article 127 CPEUM, with application of thesis P./J. 87/97 and the principle of non-regression; pending final systematization in the Judicial Gazette of the Federation.
Constitutional Court of Colombia: rulings on Legislative Act 01 of 2005 and the requirement for transition regimes in constitutional reforms affecting pension rights; doctrine on legitimate trust in pension matters.
Constitutional Court of Spain: STC 189/1987, of November 24 (BOE no. 306, of December 23, 1987), regarding constitutional limits on legislative reduction of Social Security benefits recognized under prior regime. STC 97/1990, of May 24