Background <p>Prior evidence suggests that journals requiring open data are associated with higher levels of data sharing in the published psychology literature. Data sharing policies are not, however, consistently implemented or enforced. The American Psychological Association (APA), in 2020, signed onto the Transparency and Openness Promotion Guidelines, which promote increasingly stringent data sharing policies. The current study examined self-reported data sharing in APA journals and whether stricter policies are linked to higher levels of self-reported data sharing.</p> Methods <p>We assessed self-reported data sharing practices in 1,250 articles published between 2023 and 2025 in 25 APA journals. Using logistic regression, we examined the association between journal policy level and self-reported data sharing. We then applied post-stratification weighting, based on the actual distribution of policy levels across APA journals and their associated percentages of data sharing, to estimate the overall percentage of self-reported data sharing.</p> Results <p>We estimated overall self-reported data sharing to be 30.3% (95% CI [27.7, 33.0]). Journal policy stringency was strongly associated with self-reported data sharing: among journals with no data sharing policy, 15.0% of articles reported shared data (30 out of 200; 95% CI [10.7, 20.6]); among journals that mandate that authors reveal whether they shared their data, 26.4% of articles reported shared data (145 out of 550; 95% CI [22.8, 30.2]), and among journals that mandate data sharing, 70.4% of articles reported shared data (352 out of 500; 95% CI [66.2, 74.2]). At the same time, even journals with more stringent data sharing requirements did not consistently enforce their policies.</p> Conclusions <p>These results indicate that despite widespread endorsement of open science practices, data sharing is not yet a customary practice among psychology researchers. The observed self-reported data sharing practices do, however, show that more stringent journal policy requirements are associated with increased openness. While the observational nature of the present study precludes strong causal inferences, stricter journal policies may represent one potential factor relating to the adoption of data sharing practices, including the use of data embargoes and greater transparency around decisions not to share data. Overall, findings highlight a promising direction for ongoing efforts to promote openness in data sharing, while underscoring the need for future research to clarify the mechanisms that link policy to practice.</p>