Social Security Affiliation Data Shared with Castilla y León: What Changes in Medical Leave

Key data

Doctors at the Public Health Services of Castilla y León (Sacyl) have had access since August 11, 2026 to Social Security affiliation data when issuing temporary incapacity (IT) reports. The objective is for the physician to know the worker's actual occupation, without depending exclusively on what the worker declares in the consultation.

The mechanism is formalized through an agreement between the National Institute of Social Security (INSS), the General Treasury of Social Security (TGSS) and the Community of Castilla y León, published in the BOE on the same day it entered into force. Its legal basis is article 77.1 of the Consolidated Text of the General Social Security Law (TRLGSS) and the inter-administrative cooperation framework established in Law 40/2015.

What does this regulation establish?

The agreement creates an information flow between three organizations so that it reaches the doctor at the moment the medical leave report is issued:

• TGSS transfers affiliation data to the INSS.
• INSS forwards it to the Public Health Services of Castilla y León (Sacyl).
• Sacyl physicians access this information when managing IT reports.

What data is shared? Information relating to the worker's occupation and affiliation status: professional category, type of contract, activity, contribution regime. Objective information that previously the doctor only knew if the patient themselves provided it, with the margin for error or omission that implies.

The temporal scope of application of the enhanced control covers the first 365 days of each temporary incapacity process. This is the period when IT management is primarily the responsibility of the company and the mutual insurance company, before the INSS assumes direct control.

Economic and operational impact

For companies, absenteeism due to temporary incapacity has a significant direct and indirect cost: salary supplements during leave, replacement costs, loss of productivity and contributions. Greater rigor in verifying the worker's actual occupation when issuing the report has two practical effects:

• Reduction of inappropriate leave: if the doctor knows that the worker performs an activity incompatible with the declared condition, they can adjust the diagnosis or report with greater precision.
• Greater coherence between the leave and the job position: the alignment of the report with actual occupation can shorten unnecessarily prolonged IT processes or, conversely, better protect the worker whose actual activity is more demanding than they declared.

From an operational perspective, companies do not need to do anything technical to activate this mechanism: the data exchange is inter-administrative. However, they must ensure that their affiliation data with the TGSS is up to date and accurate, because that information is what will reach the doctor.

Who does it affect?

• Companies with workers in Castilla y León: any company, regardless of size or sector, that has employees affiliated with Social Security in this autonomous community.
• Workers affiliated with Social Security in Castilla y León: their occupation and affiliation data will be available to the Sacyl physician during the first 365 days of leave.
• Sacyl physicians: they are the direct users of the new information flow when issuing IT reports.
• Mutual insurance companies collaborating with Social Security: the enhanced control during the first 365 days of IT affects the period when mutual insurance companies manage leave processes together with companies.
• HR departments and labor advisors: they must understand the new framework to correctly manage IT processes and advise their clients.

Practical example

A worker at a construction company in Valladolid requests medical leave claiming that their work is "administrative" and that physical effort is minimal. Until now, the Sacyl doctor only had what the patient declared in the consultation.

With the new agreement, the physician can consult that worker's affiliation data in the TGSS through the INSS: registered professional category, contribution regime and type of activity. If the affiliation data reflects that they are a first-class construction foreman, the doctor has objective information to assess the leave with greater precision, adjust the estimated duration or refer for a more detailed evaluation.

For the company, this means that the IT report issued is more likely to reflect the reality of the position, which can influence subsequent management with the mutual insurance company and the actual duration of the process.

What should companies do now?

1. Verify that affiliation data with the TGSS is up to date: professional category, contribution group and activity for each worker must reflect the reality of the position. This is the data that will reach the doctor.
2. Review contracts and registrations with Social Security: discrepancies between the signed contract and the category registered with the TGSS can generate inconsistencies in the new information flow.
3. Inform HR managers and labor advisors: they must know that, from August 11, 2026, Sacyl physicians access affiliation data when issuing IT reports in Castilla y León.
4. Coordinate with the mutual insurance company: in IT processes within the first 365 days, the mutual insurance company is a key player. Make sure it is aware of the new verification framework.
5. No technical action is required before the administration: the data exchange is automatic between TGSS, INSS and Sacyl. The company's responsibility is to keep its affiliation data correct.

Official source

Consult complete regulation in official source

Notice: This article is for informational purposes only and does not constitute legal advice. For specific decisions, consult a qualified professional. Source: https://www.boe.es/diario_boe/txt.php?id=BOE-A-2026-17567